Furnace seal



E. W. DANY FURNAGE SEAL Feb.- 10, 1942.

3 Sheets-Sheet 2 Filed April 5, 1940 El w. DANY FURNAGE SEAL Feb# 10, 1942.

Filed April 5,` 1940 3 Sheets-Sheet 3- wm n .NN

. INVENTOR. rz/Vfl@ WDA/Vy Patented Feb. 10, 1942 UNTED STTES FURNAC'E SEAL Elmer W. Dany, Brecksville, (Ehio, assignor to Ferro Enamel Corporation, Cleveland, Ohio, a

corporation of Ohio Application April 5, 1940, Serial No. 328,070

4 Claims.

This invention relates to furnace constructionv and more particularly to an improved form of slot seal for enameling furnaces having a slot, extending the full length of the roof, through which the hook rods for supporting the ware in the furnace project. In furnaces for porcelain enameling, or other heating operations, it has been proposed to construct the furnaces with an elongated heating chamber having a slot extending lengthwise of the roof of the chamber. Such furnaces may be either of the straight through or circular or U-shaped type and a conveyor track is mounted above the roof slot. A chain type conveyor, supported from the track, moves a plurality of spaced rods which extend through the slot into the furnace chamber. Suitable work supporting means are provided on the lower ends of the rods.

In this type of furnace it is important to prevent, insofar as possible, the escape of heat through the slot. Furthermore, in porcelain enameling operations particularly, a serious problem is encountered due to the dropping of scale, dirt, etc. down through the slot on to the ware which is being burned with the resulting production of defective articles. To prevent the escape of heat and the entry of dirt into the furnace articulated shoe plates have been used to cover the slot of the furnace. These shoe plates are usually carried by the work supporting rods and may be provided with some means for eecting a sliding seal between the plates and ,the furnace top.

It is among the objects of my present invention to provide an improved shoe plate construction and assembly of supporting elements therefor whereby the ware supporting rods will be centered in the furnace slot and prevented from striking the sides of the slot, an efficient heat seal will be obtained, and the dropping of dirt or scale down on to the ware will be effectively prevented.

The above and other objects of my invention will appear from the following description of a preferred form thereof, reference being had to the accompanying drawings, in which- Figure 1 is a fragmentary vertical cross-sectional view of a furnace roof showing the slot in the top of the furnace and sealing means therefor.

Figure 2 is a view taken on line 2-2 of Figure 1 and illustrating the conveyor and work supporting rods in side elevation, the shoe plates being shown in section.

Figure 3 is a fragmentary plan view of a Vsupported by suitable hangers 3 and 4 from the transverse supporting member 5. The roof members I and 2 are spaced to form the roof slot 6, the edges of which are defined by the refractory blocks 'I and 8. The blocks 'I and 8 are arranged in rows extending the full length of the furnace roof to define an elongated slot through which the work supporting bars 9 may travel. The roof is preferably covered with insulating material I0 and the blocks 'I and 8 slope `inwardly to form a slot 3 which is relatively narrow at its top as seen at 6 and relatively wide at the bottom. The blocks 'I and 8 are formed with nose portions 'I' and 8 which lform one wall of the longitudinally extending slots or grooves l" and 8". I I and I2 are co-extensive with the length of the slot 6 and are supported by suitable bolts I3 and I4 on angles I5 and I6 carried by the vertical hangers Il and I8. The upper ends of the hangers II and I8 are secured to the transverse Asupport 5 and it will be understood that a plurality of these hangers I1 and I3 will be provided for the shoe plate supports II and I2 at spaced intervals throughout their length.

Secured to and supported with the shoe plate supports or tracks II and I2 by the bolts I3 and I4 respectively vare elongated guide flange members I9 and 20. As seen in'Figure 1, these may be spaced from the horizontal portions II' and I2 of the shoe plate supports by Washers 2I and 22 and washers 23 and 24 may be interposed between the angle guides I9 and 20 and the supporting brackets I5 and I5. The holes in the horizontal portions of the guides I9 and 20 through which the bolts I3 and I4 extend are preferably in the form of transversely extending slots so that the spacing of the gui-des may be adjusted.

The upwardly extending lips IIl and I2 of the shoe plate supports assist in preventing scale and dirt from dropping inwardly from the top surface of these supports into the furnace and l' The shoe plate supports spaced elongated slots and 25 are formed in the shoe plate supporting surfaces |I and |2 (see Fig. 3),

The work carrying bars 9 are supported from hangers 21, each of which is provided with a pair of wheels 28 supported on the bottom ange of the I-beam 29 which extends the full length of the furnace above the slot 6 and forms a track for the work carrying conveyor structure. The hangers 2'I and bars 9 are moved by and maintained in the proper spaced relation by the chain 30.

The open slot 6 in the furnace top is sealed by a plurality of shoe plates indicated at P. Each plate, as is best seen in Figure 2, extends between two adjacent work carrying bars 9 and adjacent plates overlap each other to form an articulated sealing structure. Downwardly extending flanges 3| are formed on each edge of each shoe plate P and have sliding engagement i with the surface of the horizontal portions Il and I2 of the shoe plate supports. The overall width of the plates P is less than the clearance between the vertical guides I9 and 20 and it will be observed from inspection of lFigure 1 that a limited' sidewise movement of the plates is permitted. However, the `vertical guides I9 and 29 restrict this lateral movement of the shoe plates in such a manner that striking of the bars 9 against the nose portions 'I' an-d 8 of the slot 6 is positively prevented. This also prevents undesired swaying of the bars 9 and the work carried thereby. In previous shoe plate arrangements with which I am familiar diiculty has been experienced due to swinging of the work supporting bars to such an extent that they strike the surfaces of the slot. This causes refractory material, etc., to fall down through the slot on to the work, which, as has been noted above, is extremely undesirable.

Referring to Figures 4 and 5, each shoe plate P is formed with an elongated slot 32 at one end and an upwardly projecting boss 33 adjacent the other end. The plates are also offset as indicated at 35 which offset is arcuate in form as seen in Figure 3. When assembled in working position the boss 33 of one shoe plate projects up through the slotted opening 32 of the next shoe plate and the extension 35 of the rst shoe plate lies below and within the offset portion of the next shoe plate. The work carrying bars project through the holes 36 in the bosses 33 and collars 3'| are mounted on the bars S, as seen in Figures 1 and 2, to prevent the shoe plates from dropping down when the plates leave the end of the furnace slot. It is understood that the chain 30 is` endless and suitable guides or sprockets are provided beyond the ends of the furnace slot so that the chain and shoe plates form a continuous loop, one reach of which, in a straight through furnace, is always disposed in slot closing position. By providing the curved offset portions 34 and the curved ends of the shoe plates, articulation of the plates in going around the bends at the entering and exit ends of a straight through furnace chamber, or around the curved portions of a circular or U-shaped furnace, is facilitated.

The bottom surfaces of all of the flanges 3| lie in the same plane and slide along on the horizontal supports I|' and I2. Due to the high temperatures encountered in furnace operation a certain amount of scale is unavoidably formed and also dirt and dust collects on the shoe plates. My improved structure prevents,

in a large measure, such dirt and scale from falling into the furnace. Theslots 25 and 26 permit any scale or foreign material which collects upon the surface of the shoe plate supports to drop through and fall outwardly on to the top of the furnace structure. The flanges 3| partially overlie the slots 25 and 26 when the shoe plates are in centered position as shown in Figure 1 but the guide anges I9 and 20 prevent such a degree of lateral movement of the shoe plates as would open either of the slots 25 and 26 to the interior atmosphere of the furnace. Thus, the flanges I9 and 29 not only serve to center and prevent swaying of the bars 9 but also make possible the use of the scale discharging slots 25 and 2S by preventing these slots from being uncovered at any time with resulting leakage to the furnace interior. Lips Il and I2 tend to retain any material which may collect inside of the flanges 3|, but if any scale or the like should be forced over the lips and |2" it will drop down into the elongated gooves l" and 8 and will not fall into the furnace.

By definitely limiting the lateral movement of the shoe plates and work supporting bars by means of the vertical flanges I9 and 2 I am able to make the top opening 6 of the slot 6 of minimum width. This results in exposing the least possible surface of the shoe plates P to the direct heat of the interior of the furnace with a consequent reduction in scaling of the shoe plates and increase in life thereof. As the work supporting bars 9 are supported at their upper ends by the wheels 28, and are provided with intermediate sway preventing means in the form of shoe plates P, the lower ware supporting ends of the bars which are disposed in the furnace chamber cannot swing sidewise excessively during operation and, as explained above, this permits me to employ a narrower slot 6 than would otherwise be possible with resulting decrease in heat loss.

Moreover, the guiding of the shoe plates positively prevents the bars from swinging into contact with the refractory nose blocks which define the slot. By making these slot defining members of refractory material the expense of high temperature resisting alloy metal is avoided and replacement and repair costs are greatly reduced'. By forming the blocks I and 8 with the grooves l and 8, into which the vertical webs 38 and 39 of the shoe plate supports project, I provide an effective means for collecting foreign material which m-ight otherwise fall through the slot on to the ware. As seen in Figure 1, the webs 38 and 39 engage the outer walls of the grooves l" and 8" and thus a complete seal is provided for the top of the furnace.

Although I have described the illustrated embodiment of my invention in considerable detail it will be understood that variations and modifications may be made inthe form of my improved furnace slot construction without departing from the spirit of my invention. For example, the vertical guiding and restricting flanges I9 and 29 might be replaced by a plurality of closely spaced rollers if so desired, and the adjacent shoe plates might be made of different lengths to vary the spacing of the work carrying bars '9. I do not, therefore, wish to be limited to the exact form of my invention herein shown and described, but desire to claim all embodiments thereof coming within the scope of the appended claims.

I claim:

1. In combination in apparatus of the type described, members defining a slot, a plurality of work supporting bars, means for supporting and moving said bars through said slot, a plurality of overlapping articulated shoe plates mounted on said bars and movable therewith, supporting tracks for said shoe plates on each side of said slot, said supporting tracks having openings adjacent the point of engagement between said tracks and said shoe plates, guide means for restricting lateral movement of said shoe plates and ware supporting bar to less than the width of said slot, said guide means also being adapted to so restrict lateral movement of said shoe plates as to prevent said openings from establishing communication from said slot to the outside of said shoe plates.

2. In combination, refractory members defining the edges of a slot and having grooves in their upper surfaces extending parallel to the slot, shoe plate supporting members above said grooves and extending parallel to said slot on each side thereof, a plurality of shoe plates having surfaces slidably supported on said sup.- porting members, guide flanges extending upwardly from said supporting members for limiting the lateral movement of said shoeplates, and upwardly projecting lips on the inner edges Cil of said shoe plate supporting members and above said grooves.

3. In combination, refractory members defining the edges of a slot and having grooves in their upper surfaces extending parallel to the slot, shoe plate supporting members above said grooves and extending parallel to said slot on each side thereof, a plurality of shoe plates having surfaces slidably supported on said supporting members, guide flanges extending upwardly from said supporting members for limiting the lateral movement of said shoe plates, upwardly projecting lips on the inner edges of said shoe plate supporting members and above said grooves in said refractory members, said supporting members having apertures therethrough and spaced outwardly from said lips, and means for moving said shoe plates over said slot.

4. A shoe plate structure for a furnace including parallel spaced shoe plate tracks having shoe plate supporting surfaces and scale escapement holes through said surfaces, said holes communicating at their lower ends with the outside of the furnace, shoe plates having surfaces engaging said supporting surfaces, and guide means for said shoe plates positioned to limit lateral movement thereof.

ELMER W. DANY. 

